Allow manifest handlers to declare keys they depend on that must be parsed before them.

chrome/browser/extensions/updater/extension_updater_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <list>
 #include <map>
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 440 matching lines @@
       : ui_thread_(BrowserThread::UI, &loop_),
         file_thread_(BrowserThread::FILE, &loop_),
         io_thread_(BrowserThread::IO, &loop_) {
   }
 
   virtual ~ExtensionUpdaterTest() {
   }
 
   virtual void SetUp() OVERRIDE {
     prefs_.reset(new TestExtensionPrefs(loop_.message_loop_proxy()));
-    extensions::ManifestHandler::Register(extension_manifest_keys::kUpdateURL,
-                                          new extensions::UpdateURLHandler);
+    extensions::ManifestHandler::Register(
+        extension_manifest_keys::kUpdateURL,
+        make_linked_ptr(new extensions::UpdateURLHandler));
   }
 
   virtual void TearDown() OVERRIDE {
     // Some tests create URLRequestContextGetters, whose destruction must run
     // on the IO thread. Make sure the IO loop spins before shutdown so that
     // those objects are released.
     RunUntilIdle();
     prefs_.reset();
   }
 
@@ skipping 1220 matching lines @@
 // -prodversionmin (shouldn't update if browser version too old)
 // -manifests & updates arriving out of order / interleaved
 // -malformed update url (empty, file://, has query, has a # fragment, etc.)
 // -An extension gets uninstalled while updates are in progress (so it doesn't
 //  "come back from the dead")
 // -An extension gets manually updated to v3 while we're downloading v2 (ie
 //  you don't get downgraded accidentally)
 // -An update manifest mentions multiple updates
 
 }  // namespace extensions